Page 477 - Concise Pathology for Exam Preparation ( PDFDrive )

462 SECTION II Diseases of Organ Systems

(b) Microscopic examination
(c) Bacteriologic examination
2. Blood examination
(a) Blood urea (BUN)
(b) Serum creatinine
(c) Serum electrolytes
(d) Serum protein
(e) Serum cholesterol
(f) Serum uric acid
3. Renal clearance tests (CT)
(a) Tests for glomerular function
(i) Inulin CT
(ii) Creatinine CT
(b) Tests for tubular function:
(i) Urea CT
(ii) Paraamino hippuric (PAH) CT
4. Concentration and dilution tests
(a) Concentration test (fluid deprivation test)
(b) Dilution test (excess fluid intake test)
5. Others
(a) Intravenous pyelography
(b) Ultrasonography
(c) Arteriography
(d) FNAC/renal biopsy

Q. Differentiate between acute and chronic renal failure.

Ans. Differences between acute and chronic renal failure are tabulated in Table 16.1.

TABLE 16.1. Differences between acute and chronic renal failure

Features Acute renal failure Chronic renal failure
Definition • Rapid onset of renal dysfunction; may • Progressive and irreversible deteriora-
be reversible tion of renal function due to slow de-
struction of renal parenchyma
• Manifests with oliguria/anuria and in- • Manifests with azotaemia and acidosis
crease in urea and creatinine
Causes Prerenal (ischaemia and hypovolaemia), All chronic nephropathies like chronic
renal (vascular, glomerular and tubular glomerular diseases as well as chronic
disorders) and post-renal (obstruction tubulointerstitial diseases
in ureters, bladder and urethra)
Metabolic acidosis Poorly tolerated Well tolerated
Clinical presentation Three patterns: Four stages:
1. Syndrome of acute nephritis 1. Diminished renal reserve (50% GFR)
2. Syndrome accompanying tubular dys- 2. Renal insufficiency (20–50% GFR)
function 3. Renal failure (5–20% GFR)
3. Prerenal syndrome 4. End-stage renal disease (,5% GFR)
Urine output Markedly decreased Normal
Serum electrolytes
Calcium Normal/low Low
Phosphate Increased Markedly increased
Sodium Decreased Markedly decreased
Potassium Increased Markedly increased
Haemoglobin Normal Reduced (normocytic normochromic
anaemia; in case of blood loss, micro-
cytic hypochromic anaemia)
Serum parathormone Normal Increased
Alkaline phosphatase Normal Increased

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